Dihydropyridines are represented by the following general formula (I): ##STR2##
(where R.sup.1 nitrophenyl group and R.sup.2, R.sup.3, and R.sup.4 are all lower alkyl groups). Among these dihydropyridines, the compound with a 3-nitrophenyl group as R.sup.1, an isopropyl group as R.sup.2, and methyl groups as R.sup.3 and R.sup.4 is called nilvadipine. It is publicly known as a calcium antagonist, and has had wide clinical usage, for example, as a hypotensive drug. Recently, nicardipine (hydrochloride), another calcium antagonist, has been shown to increase peripheral blood flow in the retina of rabbits. In the case of nilvadipine, however, there had been no information about its effects on the peripheral circulation of the retina or its therapeutic actions on ophthalmic diseases.